1. Field of the Invention
The present invention relates to an improved electrical circuit having a thyristor such as a thyristor inverter or a thyristor chopper where the circuit includes circuitry for turning off the thyristor.
2. Description of the Prior Art
In general, thyristors have been used for imparting ON-OFF control to electric circuits such as an inverter or a chopper. The electrical circuit having a thyristor usually includes a turn-off circuit for turning off the thyristor. The turn-off circuit applies a reverse voltage (that is a voltage to give a positive polarity to the cathode and a negative polarity to the anode) between the anode and cathode of the thyristor to turn off the thyristor. The complexity of prior art circuits for turning off a thyristor has led to a need for a simple and uncomplicated circuit which can perform this function. It is preferable to turn off the thyristor in as short a time as possible. This is especially important for circuits where the thyristor is repeatedly turned on and off for short repeated periods such as an inverter or a chopper.